ul.nav-tree {
  list-style: none;

  ul.nav-tree {
    margin-left: 30px;
  }

  li {
    position: relative;
    margin-left: -15px;

    a + ul.nav-tree {
      margin-top: 2px;
    }

    a {
      text-indent: 25px;
    }

    &.active span.opener {
      color: #fff;
    }

    span.opener {
      position: absolute;
      top: 0;
      left: 0;
      padding: 10px 10px 10px 15px;
      color: $link-color;
      z-index: 1;

      &.closed {
        span.tree-icon-opened {
          display: none;
        }
        span.tree-icon-closed {
          display: block;
        }
      }

      &.opened {
        span.tree-icon-open {
          display: block;
        }
        span.tree-icon-closed {
          display: none;
        }
      }
    }
  }
}
